Merge pull request #1908 from prometheus/on-dates

Add various time and date functions

promql/functions.go

@@ -18,6 +18,7 @@ import (
 	"regexp"
 	"sort"
 	"strconv"
+	"time"
 
 	"github.com/prometheus/common/model"
 
@@ -859,6 +860,69 @@ func funcVector(ev *evaluator, args Expressions) model.Value {
 	}
 }
 
+// Common code for date related functions.
+func dateWrapper(ev *evaluator, args Expressions, f func(time.Time) model.SampleValue) model.Value {
+	var v vector
+	if len(args) == 0 {
+		v = vector{
+			&sample{
+				Metric: metric.Metric{},
+				Value:  model.SampleValue(ev.Timestamp.Unix()),
+			},
+		}
+	} else {
+		v = ev.evalVector(args[0])
+	}
+	for _, el := range v {
+		el.Metric.Del(model.MetricNameLabel)
+		t := time.Unix(int64(el.Value), 0).UTC()
+		el.Value = f(t)
+	}
+	return v
+}
+
+// === days_in_month(v vector) scalar ===
+func funcDaysInMonth(ev *evaluator, args Expressions) model.Value {
+	return dateWrapper(ev, args, func(t time.Time) model.SampleValue {
+		return model.SampleValue(32 - time.Date(t.Year(), t.Month(), 32, 0, 0, 0, 0, time.UTC).Day())
+	})
+}
+
+// === day_of_month(v vector) scalar ===
+func funcDayOfMonth(ev *evaluator, args Expressions) model.Value {
+	return dateWrapper(ev, args, func(t time.Time) model.SampleValue {
+		return model.SampleValue(t.Day())
+	})
+}
+
+// === day_of_week(v vector) scalar ===
+func funcDayOfWeek(ev *evaluator, args Expressions) model.Value {
+	return dateWrapper(ev, args, func(t time.Time) model.SampleValue {
+		return model.SampleValue(t.Weekday())
+	})
+}
+
+// === hour(v vector) scalar ===
+func funcHour(ev *evaluator, args Expressions) model.Value {
+	return dateWrapper(ev, args, func(t time.Time) model.SampleValue {
+		return model.SampleValue(t.Hour())
+	})
+}
+
+// === month(v vector) scalar ===
+func funcMonth(ev *evaluator, args Expressions) model.Value {
+	return dateWrapper(ev, args, func(t time.Time) model.SampleValue {
+		return model.SampleValue(t.Month())
+	})
+}
+
+// === year(v vector) scalar ===
+func funcYear(ev *evaluator, args Expressions) model.Value {
+	return dateWrapper(ev, args, func(t time.Time) model.SampleValue {
+		return model.SampleValue(t.Year())
+	})
+}
+
 var functions = map[string]*Function{
 	"abs": {
 		Name:       "abs",
@@ -872,12 +936,6 @@ var functions = map[string]*Function{
 		ReturnType: model.ValVector,
 		Call:       funcAbsent,
 	},
-	"increase": {
-		Name:       "increase",
-		ArgTypes:   []model.ValueType{model.ValMatrix},
-		ReturnType: model.ValVector,
-		Call:       funcIncrease,
-	},
 	"avg_over_time": {
 		Name:       "avg_over_time",
 		ArgTypes:   []model.ValueType{model.ValMatrix},
@@ -920,6 +978,27 @@ var functions = map[string]*Function{
 		ReturnType: model.ValScalar,
 		Call:       funcCountScalar,
 	},
+	"days_in_month": {
+		Name:         "days_in_month",
+		ArgTypes:     []model.ValueType{model.ValVector},
+		OptionalArgs: 1,
+		ReturnType:   model.ValVector,
+		Call:         funcDaysInMonth,
+	},
+	"day_of_month": {
+		Name:         "day_of_month",
+		ArgTypes:     []model.ValueType{model.ValVector},
+		OptionalArgs: 1,
+		ReturnType:   model.ValVector,
+		Call:         funcDayOfMonth,
+	},
+	"day_of_week": {
+		Name:         "day_of_week",
+		ArgTypes:     []model.ValueType{model.ValVector},
+		OptionalArgs: 1,
+		ReturnType:   model.ValVector,
+		Call:         funcDayOfWeek,
+	},
 	"delta": {
 		Name:       "delta",
 		ArgTypes:   []model.ValueType{model.ValMatrix},
@@ -962,11 +1041,12 @@ var functions = map[string]*Function{
 		ReturnType: model.ValVector,
 		Call:       funcHoltWinters,
 	},
-	"irate": {
+	"hour": {
-		Name:       "irate",
+		Name:         "hour",
-		ArgTypes:   []model.ValueType{model.ValMatrix},
+		ArgTypes:     []model.ValueType{model.ValVector},
+		OptionalArgs: 1,
 		ReturnType:   model.ValVector,
-		Call:       funcIrate,
+		Call:         funcHour,
 	},
 	"idelta": {
 		Name:       "idelta",
@@ -974,6 +1054,18 @@ var functions = map[string]*Function{
 		ReturnType: model.ValVector,
 		Call:       funcIdelta,
 	},
+	"increase": {
+		Name:       "increase",
+		ArgTypes:   []model.ValueType{model.ValMatrix},
+		ReturnType: model.ValVector,
+		Call:       funcIncrease,
+	},
+	"irate": {
+		Name:       "irate",
+		ArgTypes:   []model.ValueType{model.ValMatrix},
+		ReturnType: model.ValVector,
+		Call:       funcIrate,
+	},
 	"label_replace": {
 		Name:       "label_replace",
 		ArgTypes:   []model.ValueType{model.ValVector, model.ValString, model.ValString, model.ValString, model.ValString},
@@ -1010,6 +1102,13 @@ var functions = map[string]*Function{
 		ReturnType: model.ValVector,
 		Call:       funcMinOverTime,
 	},
+	"month": {
+		Name:         "month",
+		ArgTypes:     []model.ValueType{model.ValVector},
+		OptionalArgs: 1,
+		ReturnType:   model.ValVector,
+		Call:         funcMonth,
+	},
 	"predict_linear": {
 		Name:       "predict_linear",
 		ArgTypes:   []model.ValueType{model.ValMatrix, model.ValScalar},
@@ -1095,6 +1194,13 @@ var functions = map[string]*Function{
 		ReturnType: model.ValVector,
 		Call:       funcVector,
 	},
+	"year": {
+		Name:         "year",
+		ArgTypes:     []model.ValueType{model.ValVector},
+		OptionalArgs: 1,
+		ReturnType:   model.ValVector,
+		Call:         funcYear,
+	},
 }
 
 // getFunction returns a predefined Function object for the given name.

promql/testdata/functions.test

@@ -363,3 +363,46 @@ eval instant at 1m quantile_over_time(2, data[1m])
 	{test="two samples"} +Inf
 	{test="three samples"} +Inf
 	{test="uneven samples"} +Inf
+
+clear
+
+# Test time-related functions.
+eval instant at 0m year()
+  {} 1970
+
+eval instant at 0m month()
+  {} 1
+
+eval instant at 0m day_of_month()
+  {} 1
+
+# Thursday.
+eval instant at 0m day_of_week()
+  {} 4
+
+eval instant at 0m hour()
+  {} 0
+
+# 2008-12-31 23:59:59 just before leap second.
+eval instant at 0m year(vector(1230767999))
+  {} 2008
+
+# 2009-01-01 00:00:00 just after leap second.
+eval instant at 0m year(vector(1230768000))
+  {} 2009
+
+# 2016-02-29 23:59:59 Febuary 29th in leap year.
+eval instant at 0m month(vector(1456790399)) + day_of_month(vector(1456790399)) / 100
+  {} 2.29
+
+# 2016-03-01 00:00:00 March 1st in leap year.
+eval instant at 0m month(vector(1456790400)) + day_of_month(vector(1456790400)) / 100
+  {} 3.01
+
+# Febuary 1st 2016 in leap year.
+eval instant at 0m days_in_month(vector(1454284800))
+  {} 29
+
+# Febuary 1st 2017 not in leap year.
+eval instant at 0m days_in_month(vector(1485907200))
+  {} 28